Dry cleaning solvents containing DPTB and other surfactants

ABSTRACT

A method for dry-cleaning garments which comprises treating the garments with a mixture of dipropylene glycol tertiary-butyl ether (DPTB) and water for a period of time sufficient to effect dry-cleaning, wherein the weight ratio of DPTB to water is at least 9:1.

CROSS REFERENCE TO RELATED APPLICATION

[0001] The present invention claims priority benefit of U.S. ProvisionalPatent Application No. 60/211,301 filed Jun. 13, 2000, the disclosure ofwhich is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a novel glycol etherdry-cleaning solvent and a method for effecting dry-cleaning using saidsolvent. More particularly, the present invention relates to a glycolether solvent that not only is comparable or superior toperchloroethylene in its attributes and benefits, and does not sufferfrom the serious environmental, health and occupational negatives andproblems associated with the use of perchloroethylene, but which alsorepresents an improvement over the current glycol ether solvents thatare contemplated as replacements for perchloroethylene.

[0003] Perchloroethylene is the most widely used dry-cleaning solvent,and is commonly referred to (and will be referred to sometimeshereinafter) as “perc”. Perc is a chlorinated hydrocarbon-based solvent.It is the dry-cleaning solvent of choice throughout North America,Europe and Asia.

[0004] In addition to perc's use in the dry-cleaning industry, it hasfound extensive use as a degreasing agent in the metals industry, in thescouring/milling of wool, and in various “clean room” applications inthe semiconductor and electronics industries. The industrial uses ofperc are approximately ten-fold greater than its use as a solvent fordry cleaning.

[0005] While perc has been found to be an effective dry-cleaning agentbecause it is non-flammable, does not damage synthetic fabrics or causeshrinkage to fabrics containing naturally occurring fibers, such aswool, and has a relatively low boiling point that permits its beingreclaimed and purified by means of ordinary distillation, it doespresent a number of other problems which present drawbacks to its use.In particular, perchloroethylene presents a number of health andenvironmental hazards that would militate against its continued use,provided a substitute solvent of comparable quality were available thatwas free of the aforementioned hazards.

[0006] Because perc is heavier than water, its disposal represents asignificant environmental risk because it will sink to the bottom of anaquifer, lake, river, and the like, with possibly resultantcontamination of the water supply. Additionally, perc vapors have beenimplicated as having a deleterious effect on the central nervous system.In addition, because it is a highly chlorinated molecule, perc has beenidentified as being a significant health hazard to cattle, and as acause of skin cancer, particularly melanoma, because of the action ofthe chlorine in perc depleting oxygen from the ozone layer. Furthermore,and of particular import, is the fact that perc is not biodegradableand, hence, will over a period of time accumulate, presenting asignificant industrial waste disposal hazard.

[0007] As the nature and seriousness of the foregoing problems becomemore and more manifest with the passage of time and with the completionof various research and clinical investigations into the nature of percand its mechanisms of action, the use of alternative solvents has beensought, but none have met with any degree of commercial success sincethey could not match the result obtained by perc as a dry-cleaningagent.

[0008] However, at this point in time, when environmental concerns arebeing rigorously monitored and policed by domestic and foreigngovernments by means of legislation and civil and even criminalprosecution, the need for a substitute solvent for perc for dry-cleaningoperations, as well as other operations, has become a matter of somedegree of urgency.

[0009] A difficulty in identifying a replacement dry-cleaning solventfor perc is that it must meet so many requirements, both as to itsefficacy as a dry-cleaning agent, i.e. high purity, non-shrinking withrespect to about 160 types of fabric, dye-fast for non-bleeding withrespect to about 900 types of dyes, a high flashpoint to render itnon-flammable and non-combustible, the ability to separate from water,effective detergency, ease of distillation, simplicity of reclamation,compatibility with existing dry-cleaning equipment, and the like, aswell as its being non-polluting to the water supply and the ozone layer,biodegradable, non-toxic, non-carcinogenic, and the like.

[0010] One proposed solvent substitute, namely propylene glycolmonomethyl ether, which is disclosed in EP 479,146 as possessing manydesirable properties, was found to be wanting in that it causes damageto weak dyes, fine yarns, and delicate fabrics, such as acetates,because of its pronounced tendency to accumulate water from theenvironment, and from fabrics being dry-cleaned. Water accumulation orwater-miscibility is also a decided negative from another aspect in thatit significantly impairs the efficiency of the dry-cleaning processbecause the dry-cleaning equipment is burdened with the handling ofexcessive quantities of water and the solvent stock is diluted and mustbe brought back to a correct ratio for stability reasons.

[0011] Propylene glycol tertiary-butyl ether (PTB) and propylene glycoln-butyl ether (PNB) were disclosed by WO 98/45523 as being superioralternatives to propylene glycol monomethyl ether. PTB and PNB weredisclosed to possess all of the dry-cleaning attributes associated withperc and none of its drawbacks. The water-absorbing capabilities of bothsolvents was disclosed to be within a range effective in preventingdamage to acetates and the tendency of woolen garments to shrink inwater. The water absorption also lowered the solvent boiling point whileraising the flashpoint. Both solvents were also disclosed to benon-pollutants of the water supply and ozone layer, biodegradable,non-toxic and non-carcinogenic. In addition, both solvents were capableof being used in existing perc dry-cleaning equipment.

[0012] Aqueous PTB and PNB dry-cleaning compositions have flashpointswithin industry standards. However, there has recently been a regulatorytrend toward a higher flashpoint standard. Furthermore, regulatoryagencies are also considering making the standard applicable toindividual components of a composition, even if the flashpoint of theoverall composition meets industry standards. Accordingly, there existsa need for dry-cleaning compositions based on higher flashpoint glycolethers.

[0013] The conventional wisdom has been, however, that higher flashpointglycol ethers make poor dry cleaning solvents because they are tooincompatible with water. While glycol ether dry-cleaning solutionscontaining too much water are undesirable because of the consequentialshrinkage to woolens and damage to acetates, not to mention the solventdilution, a low water content hampers the ability of the dry cleaningcomposition to remove water-soluble stains, which make up the bulk ofstains to be removed from garments requiring dry cleaning. Thus, theneed for dry-cleaning compositions based on higher flashpoint glycolethers remains unsatisfied.

SUMMARY OF THE INVENTION

[0014] This need is met by the present invention.

[0015] In line with the foregoing, it is an object of the presentinvention to provide a solvent which possesses comparable, if notsuperior chemical and physical properties when compared to perc in drycleaning, the cleaning of scoured and mill wool, and the dying offabrics, while, simultaneously, protecting the environment, publichealth and safety from the many known negatives associated with the useof perc.

[0016] It is a further object of the present invention to provide asolvent which possesses comparable, if not superior chemical andphysical properties when compared to lower flashpoint glycol ethers whenused in such end-use applications.

[0017] It is a further object of the present invention to provide adry-cleaning solvent that has a specific gravity less than that ofwater.

[0018] It is still a further object of the present invention to providea dry-cleaning solvent that minimizes or eliminates the shrinkage ofwoolen garments, prevents or limits the bleeding of dyes, and which isable to treat acetates, silks, virgin wool and other delicate fabricsgently so as to avoid damage.

[0019] It is still another object of the present invention to provide asolvent for dry-cleaning, fabric dying and the cleaning of scoured andmilled wool, the individual components of which have flashpoints withinindustry standards, yet at the same time has a sufficiently low boilingpoint to allow the solvent to be reclaimed and purified via conventionaldistillation processes.

[0020] It is still yet another object of the present invention toprovide a dye solution containing dyes that are not water-soluble and asolvent that minimizes or eliminates the shrinkage of woolen fabrics anddoes not damage acetates, silks, virgin wools and other delicatefabrics, yet penetrate the fabric fiber sufficiently to form a strongdye bond to fabric fibers.

[0021] It has now been discovered that dipropylene glycol tertiary butylether (DPTB) has a flashpoint far above current industry standards, yetat the same time possesses a degree of solvency for water-soluble stainsthat is at least equivalent to, and in most cases better than, perc andthe other glycol ether dry cleaning solvents presently in commercialuse. Furthermore, this degree of solvency increases as water is added toDPTB up to the maximum quantity soluble in the solvent at roomtemperature, typically about 10% by weight of the total composition.

[0022] Therefore, according to one embodiment of the present invention,a dry-cleaning composition is provided containing dipropylene glycoltertiary-butyl ether (DPTB), water and a fabric softening agent in anamount effective to soften the fabric of garments cleaned with thedry-cleaning composition, wherein the weight ratio of DPTB to water isat least about 9:1.

[0023] DPTB absorbs water under ambient conditions to the point ofsaturation, some of which is bound as an azeotrope. Therefore,commercial grades of DPTB unavoidably contain some water. Preferred drycleaning compositions according to the present invention contain about90% by weight of DPTB and about 10% by weight of water.

[0024] The ability of DPTB to absorb water increases as the temperatureof the composition increases, so that even compositions that aremoisture saturated at room temperature will absorb water from garmentswhen heated during the dry cleaning process. The dry cleaningcompositions of the present invention will thus absorb water from thegarments being dry cleaned. The water is then separated from the solventby azeotropic distillation, with the recovery of essentially pure DPTBwith an azeotropic level of water.

[0025] Therefore, the present invention also includes a method fordry-cleaning garments using the dry-cleaning compositions of the presentinvention. Methods in accordance with this embodiment of the presentinvention treat the garments with a composition containing dipropyleneglycol tertiary-butyl ether (DPTB) and water for a period of timesufficient to effect dry-cleaning, wherein the weight ratio of DPTB towater is at least about 9:1.

[0026] The compositions of the present invention can also be used toclean, scour and mill wool. Methods in accordance with this embodimentof the present invention treat the scoured and milled wool with acomposition containing dipropylene glycol tertiary-butyl ether (DPTB)and water for a period of time sufficient to effect cleaning, whereinthe weight ratio of DPTB to water is at least about 9:1.

[0027] The compositions of the present invention can also be used forwool scouring and milling processes as well. In accordance with thisembodiment of the present invention, a method of scouring wool isprovided characterized by scouring the wool with the compositions of thepresent invention containing dipropylene glycol tertiary-butyl ether(DPTB) and water, wherein the weight ratio of DPTB to water is at leastabout 9:1. The solvent compositions of the present invention cleanlydissolve the lanolin contained in the raw wool for subsequent recoveryand purification for use as an ingredient in cosmetics and otherproducts.

[0028] According to another embodiment of the present invention, amethod is provided for milling wool, characterized by milling the woolwith a composition containing dipropylene glycol tertiary-butyl ether(DPTB) and water, wherein the weight ratio of DPTB to water is at leastabout 9:1.

[0029] The present invention further incorporates the discovery thatwater-insoluble dyes that are soluble in aliphatic glycol ethers aresoluble in the compositions of the present invention to providecompositions that may be used to dye non-woolen fabrics withsignificantly improved colorfastness. The drying times of fabrics dyedwith the dye compositions of the present invention significantlydecreased as well, yet at the same time, a stronger bond between the dyemolecules and the fabric fibers is formed.

[0030] Therefore, according to another aspect of the present invention,a composition for dyeing fabrics is provided that is a solution of awater-insoluble aliphatic glycol ether-soluble dye dissolved in asolvent containing dipropylene glycol tertiary-butyl ether (DPTB) andwater, wherein the weight ratio of DPTB to water is at least about 9:1.

[0031] According to another embodiment of the present invention, amethod is provided for dyeing fabric with the dye compositions of thepresent invention. Methods in accordance with this aspect of the presentinvention treat the fabric for a period of time sufficient to effectdyeing with a dye composition containing a solution of a water-insolublealiphatic glycol ether soluble dye dissolved in a solvent containingdipropylene glycol tertiary-butyl ether (DPTB) and water, wherein theweight ratio of DPTB to water is at least about 9:1. Methods inaccordance with the present invention further include the step of dryingthe fabric after the step of treating the fabric to effect dyeing iscompleted.

[0032] The compositions of the present invention were discovered topresent several unexpected properties in comparison to perc andcommercial glycol ether compositions. Fabrics that were cleaned or dyed,and raw wool that was milled, scoured or cleaned, with the compositionsof the present invention had virtually no residual odor, unlike raw wooland fabrics processed with perc or other commercial glycol ethercompositions. What odor that was detectable was pleasant. In addition,the odor of DPTB could not be “reactivated” with water, meaning thatvirtually no residual solvent remained in the fabric. This is incontrast to garments cleaned with perc or other commercial glycolethers, which produce a strong solvent odor if subsequently contactedwith water.

[0033] In addition, fabric that was dry-cleaned or dyed with thecompositions of the present invention dryed virtually wrinkle-free witha noticeably soft hand, particularly in comparison to fabrics that weresimilarly treated with perc, or other commercial glycol ethercompositions. Thus, fabrics cleaned or dyed with the compositions of thepresent invention require significantly less ironing or other processingto remove wrinkles in fabrics cleaned or dyed with perc or other glycolethers, and at the same time feel softer. This is a significantcommercial advantage for dry-cleaning establishments.

[0034] Other features of the present invention will be pointed out inthe following description and claims, which disclose the principles ofthe invention and the best modes which are presently contemplated forcarrying them out.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] It has been found that when dipropylene glycol tertiary-butylether (DPTB) is used in the dry-cleaning of garments, the solventpossesses all of the attributes associated with perchloroethylene andnone of its drawbacks. Furthermore, DPTB also has certain significantadvantages not possessed by perchlorethylene. The DPTB compositions ofthe present invention are non-flammable, non-combustible,non-carcinogenic, non-toxic and, of the utmost import, biodegradable.The compositions weigh less than water, i.e., the specific gravity isless than that of water.

[0036] Advantageously, the flashpoint of DPTB is higher than that ofother glycol ethers used as dry-cleaning solvents. The DPTB compositionsof the present inventions have even higher flashpoints. Yet the solventcan still be reclaimed and purified via conventional distillationprocesses, including vacuum distallation, and despite having a higherflashpoint, the solvent is still effective in the removal ofwater-soluble stains.

[0037] DPTB has been discovered to be sufficiently water-compatible toabsorb water from garments being dry-cleaned, so that the watercomponent is effectively tied-up, thus avoiding the tendency of woolengarments to shrink, while simultaneously preventing damage to acetates.

[0038] It has also been determined that solutions of DPTB and water areeffective in the cleaning of scoured and milled raw wool, as well as inthe scouring of raw wool, which involves the pulling of oils and fattyacids, e.g. lanolin, from the wool and in the milling of yarns formedthereform. Such scouring and milling operations are conducted indry-cleaning machinery employing otherwise conventional scouring andmilling techniques.

[0039] A particular advantage of the DPTB-water solutions of the presentinvention in dry-cleaning is that they do not behave like a typicalmixture, but rather, the behavior is the same as a single substance.This permits a better defined separation upon azeotropic distillation ata lower boiling point and also facilitates reclamation more effectively,at a level of 99% or greater, and also enhances purification usingconventional distillation techniques.

[0040] Of particular note, from an economic as well as an operationalstandpoint, is the ability of DPTB to separate from water by azeotropicdistillation. This is of particular significance in dry-cleaning becausegarments entering a dry-cleaning plant contain water in the form ofmoisture. As noted above, if water were not absorbed by DPTB, damage towoolen and acetate garments would occur. If the absorbed water could notthen be separated from the DPTB by azeotropic distillation, the solventwould be diluted with free water and, thus, the dry cleaning process,and its efficiency, would be seriously compromised, as would thereclaimability of the DPTB.

[0041] Furthermore, DPTB out-performs both PTB and PNB from theperspective of having an optimum combination of elevated flashpoint andwater retention. This combination prevents the bleeding of the mostfugitive dyes. Yet, the degree of moisture retention has surprisinglybeen found to be more than adequate to complete the cleaning process,but well below levels that promote the shrinkage of woolen garments.Additionally, the limited degree of miscibility avoids dilution of thesolvent stock with its dependent problems, which are not inconsiderablewhen one considers the need to replenish the solvent.

[0042] DPTB is a very effective dry-cleaning solvent because itsdetergency action breaks down solvent-soluble (water-insoluble) stain,which account for 15% of all stains found in garments and which arecaused by fatty acids. The detergency of the solvent occurs by liftingthe soiled area from a surface and by displacing it with surface activematerials that have a greater affinity for the surface than they do forthe soiled area. Yet at the same time, DPTB also deals most effectivelywith water-soluble stains, which account for more than 80% of stainsencountered in dry-cleaning, such as, for example, stains from fruit,blood, urine, sweat, etc. Despite this affinity for water-solublematerials, DPTB has been found to be most effective in limiting thebleeding of dyes and avoiding the shrinkage of man-made polymers, suchas acetates. In comparison to other glycol ethers such as PTB and PNB,the PTB exhibits an unexpectedly superior combination of detergencyaction toward solvent-soluble stains and affinity for water-solublestains.

[0043] The DPTB compositions of the present invention dry at arelatively low temperature, namely, about 55° C. This is well within thedrying requirements for fabrics constructed of fine yarns so as to avoiddamage thereto by excessive heat.

[0044] In preparing the compositions of the present invention, DPTB iscombined with an amount of water up to the maximum quantity soluble inthe DPTB at room temperature. Ambient conditions may already haveresulted in the DPTB being saturated with water. If not, water may beadded to the DPTB to obtain the desired weight ratio of solvent andwater, i.e., but never less than about 9:1. Significantly, the quantityof DPTB can be maintained at this level without damage to acetatefabrics or increased bleeding of dyes. Even if the weight ratio ofsolvent to water approaches 9:1, DPTB is still an effective dry-cleaningsolvent. Most preferred is the use of about 90% by weight of DPTB andabout 10% by weight of water, which provides the best dry-cleaningresult from the perspective of the removal of both solvent-soluble andwater-soluble stains, combined with the most efficient andcost-effective dry-cleaning operation.

[0045] While DPTB can quite successfully and efficiently clean garmentsmade of all types of textile fabrics without the need for additionalagents, such as detergents and fabric softeners, it may be desirable toinclude in the formulation one or more surfactants to enhance thedetergency action of the DPTB or PNB, by means of reducing the surfacetension of the composition. Exemplary surfactant include fatty alcoholpolyethylene glycol ethers, linear primary alcohol ethoxylates andcyclic siloxanes. Other glycol ethers suitable for use as dry-cleaningsolvents may be added as well, including PTB and PNB. Thus, dry-cleaningcompositions according to the present invention may include less than90% by weight of DPTB, provided that the weight ratio of DPTB to waterremains greater than about 9:1. Compositions according to the presentinvention may contain as little as 50% by weight of DPTB, or even less,or any quantity between 50% and 100% by weight, i.e., 55 weight %, 60weight %, 65 weight %, etc.

[0046] While fabric softening agents are not necessary to achieve drycleaning, they are beneficial and serve to enhance the dry cleaningprocess. Thus, compositions according to the present invention may alsoinclude an effective amount of one or more fabric softening agents.

[0047] It has also been determined that the DPTB compositions of thepresent invention are effective solvents for water-insoluble dyes andthe dyeing of fabrics. Dye compositions can be prepared by dissolvingaliphatic glycol ether-soluble dyes in the DPTB compositions of thepresent invention. Dyes that are water-insoluble but soluble inaliphatic glycol ethers can be readily identified by those of ordinaryskill in the art without undue experimentation by performing simplesolubility testing. Classes of water-insoluble dyes include basic orcationic dyes, dispersed dyes and vat dyes. Dye compositions areprepared by heating an effective amount of the dye with the DPTBcomposition of the present invention, with mixing until the dye iscompletely dissolved in the DPTB composition.

[0048] Fabric dying can be conducted using conventional dyeingequipment, or by using dry-cleaning machinery. The DPTB composition ofthe present invention as a solvent for the dye not only functions todissolve the dye, it also promotes the penetration of the dye into thefabric fiber to form a stronger bond between the dye molecule and thefabric fiber.

[0049] After the dyeing is completed, the fabric is dried by essentiallyconventional techniques. Fabrics dyed with aliphatic glycolether-soluble dyes dissolved in the DPTB compositions of the presentinvention exhibit faster drying times than fabrics dyed with water-baseddyes. However, the greatest advantage is that the DPTB compositions ofthe present invention permit the use of water-insoluble dyes to dyefabrics that are colorfast when the dyed fabrics are subsequently washedin water.

EXAMPLES

[0050] The following examples are set forth to illustrate more clearlythe principles and practice of the present invention. It is to beunderstood, of course, that the invention is not limited to the specificexamples.

Example 1

[0051] One of the most significant properties that a dry-cleaningsolvent should possess is limited fiber shrinkage to ensure that thefibers comprising the garment do not shrink excessively. Excessiveshrinkage deforms the garment rendering it unsuitable for future wear.Accordingly, the dry cleaning solvent which is employed must notexcessively shrink the component fibers which comprise the fabric of thegarment. In contemporary usage, garments containing virgin wool andacetate, such as the lining found in men's jackets, can ill affordshrinkage beyond established norms.

[0052] A shrinkage test was conducted with respect to virgin wool bytaking a series for of 4″×4″ patterned virgin wool swatches andimmersing then in separate containers containing each of the solventsset forth in Table I below. Approximately 10 minutes of mechanicalaction was applied to ensure that the wool fibers became totallysaturated. The test swatch was then removed and dried at constanttemperature not exceeding 55° C. The test swatch was then compared witha control material to identify any changes in the fibers to ensure thatthe patterns had not changed their dimensions.

[0053] Each of the test solvents was then analyzed to identify any fiberlost. The maximum shrinkage should not exceed 2% on the first immersiontest and is usually expected to be less than 0.25% in any subsequentimmersion test. TABLE I % Shrinkage Solvent on 1^(st) Immersion PM 2%(Propylene glycol methyl ether) PNP 2% (propylene glycol n-propylether)DPM 2% (dipropylene glycol methyl ether) PERC 2% (perchloroethylene) PTB½% (propylene glycol tertiary-butyl ether) DPTB <½% (dipropylene glycoltertiary-butyl ether)

Example 2

[0054] A shrinkage test conducted in Example 1 was repeated with 4″×4″swatches of acetate fabric. The results are set forth below in Table II,wherein it is evident from an examination of the results therein, and inTable I, that dipropylene glycol tertiary-butyl ether (DPTB) mixturesresulted in the smallest percentage of shrinkage in both virgin wool andacetate fabrics, and, in fact, reduced shrinkage by about 400% orgreater compared with the other solvents, including perc, when employedwith virgin wool, and an even greater percentage when employed withacetate fabrics. TABLE II PM 3% (propylene glycol methyl ether) PNP 3%(propylene glycol n-propel ether) DPM 2-5% (dipropylene glycol methylether) PERC 2% (Perchloroethylene) PTB ½% (propylene glycoltertiary-butyl ether) DPTB <½% (dipropylene glycol tertiary-butyl ether)

Example 3

[0055] The bleeding of dyestuffs is the bane of the dry cleaner'sexistence. The variety of dyestuffs, their differing chemicalstructures, the degree to which they are soluble or insoluble in theparticular dry cleaning solvent employed, and the like, present manifoldproblems which must be met, addressed and solved before a new drycleaning solvent can be introduced successfully.

[0056] Dye bleeding tests were conducted by taking test swatches ofvirgin wool, 1 inch×1 inch, and immersing them in separate containersfilled with each of the azeotropic solvent mixtures indicated in TableIII below. Ball bearings were added to each of the containers toincrease the impact of mechanical action on the dyes in an effort todislodge the dyes from the fabric. Increased mechanical action wasapplied for a period of ten minutes. Thereafter, the test swatch and theball bearings were removed from the solvent. Colorimeter tests employinga Bausch & Lomb SPEC 20 colorimeter were conducted on the solventremaining, which serves to indicate the relative quantity of dye removedfrom the test swatch. The results are set forth in Table III withrespect to the various solvents tested on virgin wool swatches whichhave been dyed red, green, yellow, blue and purple, respectively. Thegreater the value, the greater the degree of dye bleeding. TABLE III DYEBLEEDING Solvent Red Green Yellow Blue Purple PM 8 7 7 8 8 PNP 6 4 4 5 6DPM 6 3 5 5 6 Perc 2 2 1 1 3 PTB 2 1 1 1 3 DPTB <2   1 1 1 2

Example 4

[0057] In similar fashion to Example 3 above, swatches of variouscolored acetate fabrics were tested to determine dye bleeding in thebelow-listed solvents. The results are set forth in Table IV below.TABLE IV DYE BLEEDING Solvent Red Green Yellow Blue Purple PM 9 8 9 9 8PNP 9 8 8 8 8 DPM 8 8 8 9 8 Perc 1 1 1 2 2 PTB 2 1 1 2 2 DPTB <2   1 1 11

[0058] It is clearly evident from Tables III and IV that the azeotropicsolvent of the present invention, namely, dipropylene glycoltertiary-butyl ether (DPTB), is far superior to PM, PNP and DPM, and iscomparable to perc, as respects dye bleeding, whether the fabricemployed is virgin wool or acetate. In point of fact, the solvent of thepresent invention was in each instance, regardless of fabric type or dyecolor, significantly more effective in preventing the bleeding of dyeswhen compared with the non-perc solvents.

Example 5

[0059] A stain removal test was conducted with respect to cotton bytaking a series of 12″×12″ test panels of cotton and applying theretostandard stain items as set forth in Table V, which were then cleanedwith a perc solution containing soap. Another set of test panelssimilarly stained were cleaned with the DPTB composition of the presentinvention without soap. It will be understood by those skilled in theart that the purpose of perc is to act as a carrier for detergents,soaps, water, etc. and that most stains are typically removed by“spotting” prior to the perc dry-cleaning process. The Table V resultsdemonstrate that the use of soaps and “spotting” is less needed withDPTB. TABLE V TYPE OF STAIN PERC W/SOAP DPTB W/O SOAP Shoe Polish 50%50% Lipstick 60% 70% Face Powder 100% 100% Ketchup 40% 60% SaladDressing 70% 80%+ Animal Fat 80% 95% Mascara 90% 90% Mayonnaise 90% 90%Coffee 30% 50% Ink 30% 40% Motor Oil 80% 75% Syrup 80% 90%

[0060] It is evident with respect to each of the stains enumerated,which are quite typically encountered by dry cleaners, that DPTBperformed as well as or better than perc, which is the most prevalentsolvent employed in dry cleaning today.

[0061] As will be readily appreciated, numerous variations andcombinations of the features set forth within the foregoing descriptionand examples can be utilized without departing from the presentinvention. The foregoing examples are intended to be illustrative onlyand are not to be deemed as in any way limiting the scope of theappended claims.

What is claimed is:
 1. A composition for dry-cleaning garmentscomprising dipropylene glycol tertiary-butyl ether (DPTB), water and afabric softening agent in an amount effective to soften the fabric ofgarments cleaned with the dry-cleaning composition, wherein the weightratio of DPTB to water is at least about 9:1.
 2. The composition ofclaim 1, consisting essentially of about 90% by weight of DPTB, about10% by weight of water, and said fabric softening agent.
 3. Thecomposition of claim 1, further comprising a second surfactant.
 4. Amethod of dry-cleaning garments, comprising treating the garments for aperiod of time sufficient to effect dry-cleaning in a dry-cleaningcomposition comprising dipropylene glycol tertiary-butyl ether (DPTB)and water, wherein the weight ratio of DPTB to water is at least about9:1.
 5. The method of claim 4, wherein the period of time is sufficientto remove both solvent-soluble and water-soluble stains.
 6. The methodof claim 4, wherein said dry-cleaning composition consists essentiallyof about 90% by weight of said DPTB and about 10% by weight of water. 7.The method of claim 4, wherein said dry-cleaning composition furthercomprises a fabric softening agent present in an amount effective tosoften the fabric of the treated garments.
 8. The method of claim 4,wherein said dry-cleaning composition further comprises a secondsurfactant.
 9. A method of cleaning scoured and milled wool, comprisingtreating the scoured and milled wool with a composition to effectcleaning, said composition comprising dipropylene glycol tertiary-butylether (DPTB) and water, wherein the weight ratio of DPTB to water is atleast about 9:1.
 10. The method of claim 9, wherein said compositionconsists essentially of about 90% by weight of said DPTB and about 10%by weight of water.
 11. The method of claim 9, wherein said compositionfurther comprises a second surfactant.
 12. A composition for dyeingfabrics comprising a solution of a water-insoluble aliphatic glycolether-soluble dye dissolved in a solvent comprising dipropylene glycoltertiary-butyl ether (DPTB) and water, wherein the weight ratio of DPTBto water is at least about 9:1.
 13. The composition of claim 12, whereinsaid solvent consists essentially of about 90% by weight of said DPTBand about 10% by weight of water.
 14. The composition of claim 12,further comprising a second surfactant.
 15. A method of dyeing fabric,comprising treating the fabric to effect dyeing with a dye compositioncomprising a solution of a water-insoluble aliphatic glycolether-soluble dye dissolved in a solvent comprising dipropylene glycoltertiary-butyl ether (DPTB) and water, wherein the weight ratio of DPTBto water is at least about 9:1.
 16. The method of claim 15, furthercharacterized by the step of drying said fabric after said dyeing hasbeen effected.
 17. The method of claim 15, wherein said dye compositionsolvent consists essentially of about 90% by weight of said DPTB andabout 10% by weight of water.
 18. The method of claim 15, wherein saiddye composition further comprises a second surfactant.
 19. A method ofscouring raw wool comprising scouring raw wool with a compositioncomprising dipropylene glycol tertiary-butyl ether (DPTB) and water,wherein the weight ratio of DPTB to water is at least about 9:1.
 20. Amethod of milling scoured raw wool comprising milling said scoured rawwool with a composition comprising dipropylene glycol tertiary-butylether (DPTB) and water, wherein the weight ratio of DPTB to water is atleast about 9:1.